


A Leap In Time

by velvetjinx



Category: Captain America (Movies), Marvel Cinematic Universe, Quantum Leap
Genre: Crossover, Crossovers & Fandom Fusions, Friendship, Gen, Post-Captain America: Civil War (Movie), mild fight scene
Language: English
Status: Completed
Published: 2017-10-06
Updated: 2017-10-06
Packaged: 2019-01-09 19:08:17
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,791
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12282624
Author URL: https://archiveofourown.org/users/velvetjinx/pseuds/velvetjinx
Summary: When Sam Beckett leaps into the body of a member of the Avengers, he's on a quest to stop people from dying. But can he fool everyone, and can he succeed in saving the lives he needs to save?





	A Leap In Time

**Author's Note:**

  * For [MiraMira](https://archiveofourown.org/users/MiraMira/gifts).



> Many, many thanks to my beta reader, and for everyone who cheered me on. ❤️
> 
> I really enjoyed writing this crossover! Thank you for taking the time to read.

As Sam leaned in to kiss the bride, having managed to get his guy to the altar, he felt his atoms break apart as he leaped…

…and found himself in a new body, in the middle of what looked like a high tech lab. Everyone around him was arguing, and he looked down at his own fists, which were clenched. And one of them was… metal?

Well that was odd. 

“He's part of the team now,” a blond man was arguing. “Stop treating him like he's still a HYDRA tool.”

“How do we know that the Wakandans actually managed to fix his brain?” a dark haired man retorted, scratching idly at his short beard. “We can't really trust him.”

“Can you trust me, Tony?”

The dark haired man--Tony--shrugged. “I don't know, Cap. I don't know if I can when it comes to him. Your judgment isn't sound--you have too much history to be objective.”

Sam realized that they were talking about the person he'd leapt into, and had a sinking feeling. 

“I've had enough of this, and we're getting nowhere. You need to get over yourself, Tony. Come on, Buck.” The blond man stalked towards the door, then looked back at Sam. “You coming or what?”

Sam nodded and trotted after the man, who sighed as they walked up some stairs. 

“So, uh…” Sam began, and the man shot him a small smile. 

“I'm sorry about that, Buck. You know what Tony’s like when it comes to you. He knows that what happened with his parents wasn't your fault now, but he can still be an ass.” Sam nodded helplessly as the man stopped outside a door. “Well. Come find me if you wanna talk, okay? I've gotta call Scott. See if he wants in on this mission.”

Sam nodded again, then as soon as the man had shut the door behind him he found a secluded corner. 

“Al! Al!” he whispered, and his friend appeared next to him. 

“Hey, Sam. Wow, have you looked at yourself? That's some amount of muscle you're packing this time around. And… is that a metal arm?”

“Al, I don't have time for this! Where am I? _Who_ am I?”

Al looked at his communication device as Ziggy sent him the information. “You're in the year 2018, in the body of James ‘Bucky’ Barnes, a… wow, a genetically enhanced super soldier. You're currently in the Avengers compound, and your room is right there.”

Al pointed, and Sam ducked into the room. It was pristinely clean and tidy, and Sam raised an eyebrow before walking over to look in the mirror which hung on the wall. Al was right, he really was packing a lot of muscle. His face was handsome--high cheekbones, sharp jawline, blue-gray eyes and a hint of stubble. His hair was shoulder length and brown, and he had crinkles in the corners of his eyes. Sam hesitated to call them laughter lines. He had the strangest feeling this guy didn't have much to laugh about. 

“So what am I doing here?” Sam asked. 

“Looks like… oh, man. Looks like Bucky here runs away and ends up being hunted down by some remnants of a big, bad organization called HYDRA and killed. You have to make sure Bucky stays with the Avengers so he stays safe.”

“But how do I do that? There's nothing we can do to stop him running away after I leap again.”

Al frowned. “It looks like he runs away because he figures he'll never fit in with some of the Avengers. Change their attitudes towards him and you might stand a chance.”

“And how am I supposed to do that?” Sam murmured to himself. He could already tell that this leap was going to be a real challenge. 

***

About an hour later, Sam sat back on the bed, his head thunking against the wall. He'd managed to find some journals in Bucky's room, and had read through a good chunk of them. Many of them were disjointed, just memories, but it looked like this Bucky had done some pretty terrible stuff. 

“Al?” he called softly, and his friend appeared next to him. 

“You called?”

“Who is this Bucky? Why does he have such a dark past?”

Al typed into his communicator, and the began to read what Ziggy had returned. “James Buchanan ‘Bucky’ Barnes, born March 10, 1917… 1917? How are you over a hundred years old?”

“Maybe there's more information in there?”

“Yeah, hold on. Captured by HYDRA towards the end of the Second World War, experimented on, used as a… oh my god, Sam. He was brainwashed and used as an assassin by this HYDRA group for years, put in cryo when he wasn't needed and only taken out for missions. Escaped in 2014, eventually returned to cryo in… Wakanda?... until they found a way to undo his brainwashing, then he joined the Avengers with his best friend Steve Rogers, also known as Captain America.”

“Cap,” Sam muttered. “That must be the blond guy who stuck up for me.”

“Other members of the Avengers team are Tony Stark, Clint Barton, Natasha Romanoff, Bruce Banner, Thor--what the hell--Wanda Maximoff, Scott Lang, Sam Wilson, and Vision. No last name.”

“Okay.” Sam let out a long breath. “Maybe if I can figure out who's got a problem with Bucky and why, I can--”

There was a knock on the door, and Sam looked up, calling for whoever it was to come in. The blond man--Steve--entered, smiling. 

“Hey, Buck. We're gonna discuss what we think Loki’s next move will be. You coming?”

Sam nodded. “Sure.” He paused. “Do you think people are gonna have a problem with me being there?”

Steve's expression tightened. “I don't care if they do, Buck. You're one of the team. Tony, Natasha, Vision--they need to get over themselves.”

Trying not to look too apprehensive, Sam followed Steve down to the lab, where the others were waiting. 

Tony rolled his eyes when he saw Sam, but otherwise kept quiet. Steve sat next to a red-haired woman, who looked suspiciously at Sam as he sat down on Steve's other side. Sam guessed that she must be Natasha. 

Al appeared in front of him, and Sam jumped slightly in surprise, causing Steve to give him an odd look. Sam smiled wanly at him, then raised an eyebrow at Al. 

“Sorry, Sam,” Al said sheepishly. “Oh, hey, everyone's here!” Al proceeded to go around the room, pointing and naming the group, as Sam tried to commit everyone's names and faces to memory. “This is Steve Rogers, Bucky's best friend. They grew up together, then Steve was frozen in ice during the Second World War. That'll be how he's kept his looks. Natasha Romanoff. Ex-assassin--phew, you wanna stay on her good side! Sam Wilson, also known as the Falcon--ex military and Steve's good friend. Clint Barton, master archer. Wanda Maximoff--she apparently has some witchy powers, but Ziggy doesn't say exactly what.”

Al went up to the next guy, who had deep red skin, bending down to him to get a closer look. “Is that make-up or what? This is Vision-no-last-name--whoa. Apparently the Avengers made him, kinda like a Frankenstein deal. He has various powers, and he can fly, which is pretty awesome. Bruce Banner. This guy is a well known scientist, but is also a hulk? Whatever that is. Scott Lang. Thief, and also can shrink to the size of an ant using a special suit. I can think of some places I'd like to infiltrate if I had that suit.” When Al got to Tony, however, he paused, expression grim. “Oh boy, Sam, this one's a doozy. This is Tony Stark, billionaire, and apparently you--or rather Bucky--killed his parents while under HYDRA’s control.”

“Dammit,” Sam muttered under his breath. 

“Did you say something, Buck?” Steve asked, turning to him. 

Sam shook his head quickly. “Nope, just… clearing my throat.”

“All right, everyone,” Tony said, standing. “Pay attention. As you all know, Loki is back, and since Thor hasn't turned up yet, we're gonna have to deal with him ourselves. Luckily we have our Hulk back”--Tony grinned at Bruce, as Sam wondered again what he meant by ‘hulk’--“so he shouldn't be too much of a problem unless he brings friends. But that's always a possibility. Keep your eye out. We think he's hiding out at this warehouse in Florida, so as soon as everyone's ready we'll take the quinjet down there and investigate. Any questions?”

“Yes. Why is the dangerous assassin here? Is he coming too?” the guy with the deep red skin asked, the one that Al had named as Vision. 

Sam felt Steve bristle beside him. “Bucky is coming,” he said, his tone dangerous. “We need all the help we can get, and can I remind you that Bucky is on _our side_?”

Tony waved a hand dismissively. “I agree with Vision, but Cap makes a good point. We really do need all hands on deck, even metal ones. As long as Cap keeps an eye on his BFF there, we should be okay.”

Steve's eyes narrowed, but he kept quiet. 

Al sidled up beside Sam. “Apparently, according to Ziggy, Bucky ran away before this mission, which meant the team suffered heavier losses than they would have if Bucky had been there. That Tony guy? He dies if you don't go, as does Wanda.”

Sam nodded slightly to show he'd heard and understood, as Tony clapped his hands. 

“All right, everyone, suit up!” he said, and everyone got up, heading up the staircase. Sam went into Bucky's room, and sighed. The instinct to just get out of there was strong, and Sam knew it was bleeding through from Bucky himself. But unlike Bucky, Sam knew the consequences, so he went into the closet, taking out the suit bag labeled ‘tac gear’, and got changed. 

The flight to Florida was a lot quicker in the quinjet than by commercial airplane, and soon they were landing in Tampa. Natasha handed both Sam and Falcon a couple of guns before strapping two on herself. A van was waiting for them and they piled in. Clint drove, Tony beside him giving him directions to the warehouse. 

Everyone was on edge, and Sam wondered why. They kept calling this guy ‘Loki’, like the Norse god, but they couldn't mean him, could they?

At that moment, Al appeared in the van. “Listen, Sam, you've gotta watch yourself here,” Al said urgently. “This Loki guy? Is actually the god of mischief, all the way from Asgard, and Ziggy says he's really tricky.”

Sam nodded, keeping his face impassive, but inside he was in turmoil. A god? An actual Norse god? What the hell?

Clint parked the van outside a warehouse, and they all climbed out. Tony and Scott were in metal suits, while the other Sam wore some kind of metal backpack. Steve wore a blue uniform with a star on the front, and carried a large metal shield. Clint was carrying a bow and arrow, Natasha had a pair of handguns strapped to her, and Vision clearly wasn't human, but Wanda and Bruce weren't carrying anything. Sam watched them in his periphery, wondering. 

Around the warehouse was quiet--a little too quiet. Tony went first, pushing open the door, and they all followed him inside. Natasha drew one of her guns, and Sam did the same, using Bucky's muscle memory to guide him. The warehouse was dark, but as they walked through, the lights flashed on, and a man with shoulder length black hair walked out of the room at the back. 

“The Avengers!” he exclaimed jovially. “Well, well. A few new faces, I see.” He whistled, and a number of men ran out into the warehouse floor, armed to the teeth. There were large wooden crates around that they could use for cover, and they did so. Tony flew upwards, aiming the small rockets on his wrist at the assailants. But Sam spotted a hidden assailant in the corner with what looked like a rocket launcher, and jumped, pulling Tony down as the assailant fired. The rocket shot through the spot where Tony had been and exploded against the ceiling, tearing a huge hole in the roof. 

Tony ducked behind the crate Sam was taking cover behind and pressed a button on his helmet so his face was revealed. “I think you just saved my life there, Barnes,” Tony said, looking surprised. “I thought you would have been glad to see me dead.”

Sam shook his head. “You've got me all wrong, Tony,” he said, hoping that this would be enough to get through to the man. 

“You might be right.” Tony smiled at him, before covering his face again and firing a small missile out of his wrist over the crate at the assailants. 

Sam looked up and noticed Bruce standing in the middle of the floor. Before Sam could yell at him, he began to turn green and grow… and grow… and grow until he was enormous. Suddenly the word “hulk” made sense. 

Bruce--the hulk--stomped towards Loki and the assailants as Sam and the others covered him from behind their crates. Loki's eyes widened and he ran as the hulk came towards him, leaving his lackeys to bear the brunt of the assault. 

After that it was over in moments. Those who hadn't already been taken down by those with guns were taken down by the hulk. 

It was an exhausted but uninjured party who left the warehouse that day, and Sam was relieved. Perhaps he'd already made enough of a difference? But he didn't leap, so he knew there was something left to fix. 

When they returned to the Avengers Compound, Sam was getting changed out of his tac gear when there was a knock on the door. When he opened it, he was surprised to see Tony standing there. 

“Can I come in?” he asked, and Sam nodded. 

Tony straightened up once he was in the room, clasping his hands behind his back. “So I've been thinking, and I think I was definitely wrong about you. I mean, I've done nothing but give you a hard time since you got here and you still saved my life in a pinch. So, yeah. Thanks.” Tony held out his hand, and Sam shook it. “Glad you were there today, Barnes,” Tony added as he walked out the door. “Couldn't have done it without you.”

Sam finished getting changed into Bucky's night clothes, then curled up in the comfortable bed, falling asleep almost as soon as his head hit the pillow. 

***

The next couple of days, Sam spent a lot of time trying to talk to Natasha, but she always seemed to dodge him somehow. On the other hand, Wanda, Scott, and Clint all seemed to go out of their way to be friendly. He would find himself reading next to Wanda, or drinking coffee in the kitchen with Clint, or learning about Scott’s suit and hearing him talk about his daughter. He grew increasingly fond of each of them the more time he was there. 

Bruce was also friendly, though a little stand-offish. Not that he was ever rude, but he tended to prefer to spend time in the lab working on various scientific things rather than socializing. Sam couldn't help but wonder if this was due to the hulk being inside him, and perhaps his fear of accidentally letting it loose. 

The rest of the time he spent hanging out with Steve and Falcon, both of whom Sam liked immensely. Steve wasn't exactly talkative, but when he did say something his words had a weight to them. Falcon was a funny guy, always ribbing Sam about something or another, and Sam tried to give as good as he got. 

Sam was almost certain that he hadn't tripped up too badly at any point, but on the third day he found himself being led into the lab by Steve, where Bruce was sitting, poring over some documents. 

Steve closed and locked the door behind them, and Sam whirled around. 

“Steve?”

“Who the hell are you and what have you done with Bucky?” Steve asked, his tone quiet but somehow all the more frightening for all that. 

“Steve, I am Bucky,” Sam said, trying to pass it off with a laugh, but Steve shook his head. 

“No. You're definitely not Bucky, and you'd better tell me who you are or I'll have Bruce run painful tests on you.”

Sam's eyes widened as he noticed Al coming towards him. “Don't do it, Sam! Don't tell him!”

“I…” Sam began, and Steve took a threatening step towards him. Sam held his hands up in surrender. “My name is Sam Beckett. I'm a physicist whose main study was time travel, and I discovered that I could--but only by leaping between other people's bodies, helping them to make things right. To all intents and purposes I am Bucky, but right now the consciousness you're speaking to is mine.”

Steve's eyes narrowed. “And how do I get Bucky back?”

“He'll come back as soon as I've fixed whatever needs to be fixed, I swear. But Steve, Bucky was set to die. He was going to run away before that last mission, which would have ended with Tony and Wanda dead, and he would have been killed by guys from that group HYDRA. I'm trying to prevent that.”

“What?” Steve's jaw dropped open. “You can't be serious.”

Sam nodded. “Completely serious.”

“And you're not out the woods yet,” Al added. “Bucky is still in danger of running away, only this time Steve dies trying to save him.”

“You okay?” Steve asked. “You look like you didn't hear anything I said there.”

“I didn't. Al was talking to me.”

“Al?”

“He's my best friend, an Admiral, and he was working on my project with me. Only I can see his hologram because it's tuned into my brainwaves. He uses Ziggy, our A.I., to figure out who I've leapt into and what my purpose is for being there. He just told me that Bucky is still at risk of running away, but this time…” Sam sighed. “This time, you die trying to save him.”

Steve went pale. “How can we fix this?”

“We need to change Natasha and Vision’s attitudes. Tony is okay with Bucky now since I saved his life, but Natasha and Vision still give him a hard time.”

“Can we tell them--”

“No,” Sam interrupted Steve. “I shouldn't even have told you two, but since you figured it out--and I have no idea how, no-one ever figures it out--you kind of forced me into a corner.”

“Would you mind if a did a couple of scans?” Bruce asked. “This is really fascinating.”

Sam sighed. “Yeah, why not?”

Bruce performed a brain scan, then a full body scan, and brought the results up on the holographic screen. “Okay, this is weird,” Bruce said slowly. “Your brain is lit up in places that don't usually light up when you're in a resting state and not on some serious drugs, and your body scan shows… it's like an overlap of two bodies in one. I've never seen anything like it.”

Sam looked at the results, eyes wide. “I've never seen this before. No-one has ever known about this so no-one has ever done these tests. This really is fascinating.”

Steve laughed. “Will I leave you two mad scientists to it?”

Sam shook his head. “As great as this is, I get the feeling Bucky doesn't have a degree in physics. I don't want to do anything too bizarre in case other people notice too.”

“Okay.” Steve clapped him on the shoulder. “Then let's go talk to Natasha. I get the feeling that Vision will listen to Tony about Bucky, so we'll try and get him that way.”

Whatever Steve said to Tony must have worked, because later that day Vision came up to Sam as he sat in the common area.

“May I speak with you?” Vision asked, and Sam nodded. 

“Of course.”

“I have spoken with Tony at length, and he seems to be of the opinion that we have all misjudged you--that we should take you as the person that you are now, rather than the person you were under HYDRA’s control.” Vision looked at him searchingly. “You saved Tony's life on our last mission. Tony has berated and belittled you, but you still saved his life.”

Sam shrugged. “We're on the same team. Just because Tony didn't like me doesn't mean he should be left to die.”

“Hmm,” Vision hummed with a nod. “This is true, but perhaps not the attitude we--quite wrongly--expected you to have. Will you accept my apology?”

Sam nodded at him. “Of course.” He held out his hand and Vision shook it. 

***

“So you've charmed Tony and Vision onto your side.”

Sam turned from where he was making a cup of coffee to see Natasha standing in the doorway, eyes narrowed. 

“Coffee?” he asked. 

“What's your game, Barnes?” she said, ignoring his question. 

Sam sighed. “There's no game. I'm genuinely sorry for all the things I did when I was under HYDRA’s control, and I'm just trying to make things right.”

“You mean like the fact that you shot through me to assassinate a guy I was trying to protect?” Natasha lifted her shirt slightly to show a large bullet scar. 

Sam closed his eyes briefly. “If I could go back and stop myself, I would. I'm just trying to make amends. I know in many ways I'll never be able to, but I'm just trying to do what I can.”

Natasha looked at him thoughtfully. “You're serious, aren't you. This isn't just about your friendship with Steve. You are actually trying to make things right.”

“I really am.”

“Hmm.” Natasha frowned for a moment, before her expression cleared. “If I give you a chance, will you let me down?”

“No, Natasha,” Sam replied solemnly. “I won't let you down.”

“Well if there's one thing I understand it's the quest for redemption.” Natasha walked up to him and held out her hand, which he shook. “Just be aware that I'm still gonna be keeping an eye on you, okay?”

“Wouldn't have it any other way,” Sam replied with a nod, and he felt his atoms break apart as he leapt…

...and found himself in a forest faced by a giant grizzly bear. “Oh, boy!” he groaned, as the grizzly lumbered towards him on its hind paws. “Oh, boy.”


End file.
